CNS5:Diffuse hemispheric glioma, H3 G34-mutant: Difference between revisions

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Lynn.Hu (talk | contribs)
Lynn.Hu (talk | contribs)
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==Sites of Involvement==
==Sites of Involvement==


* Usually involves cerebral hemispheres
*Usually involves cerebral hemispheres


* Occasionally across the midline and disseminate to leptomeningeal structures.
*Occasionally across the midline and disseminate to leptomeningeal structures.


* MRI typically shows a bulky cortical mass, most commonly seen in the parietal or temporal lobe. Multifocal lesions and/or leptomeningeal dissemination can be seen along with necrosis, cysts, hemorrhage and calcification <ref>{{Cite journal|last=Vettermann|first=Franziska J.|last2=Felsberg|first2=Jörg|last3=Reifenberger|first3=Guido|last4=Hasselblatt|first4=Martin|last5=Forbrig|first5=Robert|last6=Berding|first6=Georg|last7=la Fougère|first7=Christian|last8=Galldiks|first8=Norbert|last9=Schittenhelm|first9=Jens|date=2018-12|title=Characterization of Diffuse Gliomas With Histone H3-G34 Mutation by MRI and Dynamic 18F-FET PET|url=https://pubmed.ncbi.nlm.nih.gov/30358620|journal=Clinical Nuclear Medicine|volume=43|issue=12|pages=895–898|doi=10.1097/RLU.0000000000002300|issn=1536-0229|pmid=30358620}}</ref>.
*MRI typically shows a bulky cortical mass, most commonly seen in the parietal or temporal lobe. Multifocal lesions and/or leptomeningeal dissemination can be seen along with necrosis, cysts, hemorrhage and calcification <ref>{{Cite journal|last=Vettermann|first=Franziska J.|last2=Felsberg|first2=Jörg|last3=Reifenberger|first3=Guido|last4=Hasselblatt|first4=Martin|last5=Forbrig|first5=Robert|last6=Berding|first6=Georg|last7=la Fougère|first7=Christian|last8=Galldiks|first8=Norbert|last9=Schittenhelm|first9=Jens|date=2018-12|title=Characterization of Diffuse Gliomas With Histone H3-G34 Mutation by MRI and Dynamic 18F-FET PET|url=https://pubmed.ncbi.nlm.nih.gov/30358620|journal=Clinical Nuclear Medicine|volume=43|issue=12|pages=895–898|doi=10.1097/RLU.0000000000002300|issn=1536-0229|pmid=30358620}}</ref>.


==Morphologic Features==
==Morphologic Features==
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==Individual Region Genomic Gain/Loss/LOH==
==Individual Region Genomic Gain/Loss/LOH==
 
Oncogenic amplifications in G34-DHG have been shown to be negative prognostic markers, as documented below <ref name=":4" />.
{| class="wikitable sortable"
{| class="wikitable sortable"
|-
|-
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|Amp
|Amp
|12:4,273,762-4,305,353
|12:4,273,762-4,305,353
|12p13.32  
|12p13.32
|Unk
|Unk
|Yes
|Yes
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|Homoz del
|Homoz del
|9:21,967,752-21,995,324
|9:21,967,752-21,995,324
|9p21.3  
|9p21.3
|Unk
|Unk
|Unk
|Unk
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|N/A
|N/A
|N/A
|N/A
|Found in 70% of cases of G34-DHG <ref name=":5" />  
|Found in 70% of cases of G34-DHG <ref name=":5" />
|-
|-
|3q loss
|3q loss
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==Genetic Diagnostic Testing Methods==
==Genetic Diagnostic Testing Methods==


* Targeted sequencing to identify c.103G>A p.G35R (G34R), c.103G>C p.G35R (G34R), or c.104G>T p.G35V (G34V) is diagnostic for G34-DHG.
*Targeted sequencing to identify c.103G>A p.G35R (G34R), c.103G>C p.G35R (G34R), or c.104G>T p.G35V (G34V) is diagnostic for G34-DHG.
* Pan-cancer sequencing will likely detect concurrent mutations in ''TP53, ATRX, PDGFRA'' etc.
*Pan-cancer sequencing will likely detect concurrent mutations in ''TP53, ATRX, PDGFRA'' etc.
* DNA methylation and gene expression profiling can be used to differentiate G34-DHG with other glioma subgroups.
*DNA methylation and gene expression profiling can be used to differentiate G34-DHG with other glioma subgroups.
* ''MGMT'' promoter methylation can be assessed by methylation specific polymerase chain reaction analysis (bisulfite treated DNA undergoes real-time PCR)<br />
*''MGMT'' promoter methylation can be assessed by methylation specific polymerase chain reaction analysis (bisulfite treated DNA undergoes real-time PCR)<br />


==Familial Forms==
==Familial Forms==